What To Expect From Prenatal Ultrasounds

An ultrasound scan helps determine whether your baby is healthy and assesses the progress of your pregnancy. Nearly all women will have one at some point during their pregnancies.

An ultrasound scan is also called a sonogram. A highly trained sonographer in a hospital or your doctor's office performs them.

What Is an Ultrasound Scan?

An ultrasound scan is a special screening test that allows your doctor to take a look at your growing baby. During a sonogram, high frequency sound waves go into the body and then go back to a scanner that measures the waves.

Although many women are worried that an ultrasound scan will hurt, the truth is that is doesn't. Most doctors' offices ask pregnant women to drink a large quantity of water or other liquid to ensure that their bladder is full and this is often the only uncomfortable part of the process.

During the scan, you'll lie down on the table. You'll be able to leave your clothing on, though you will need to pull up your shirt and put the waistband of your pants under your bump. Your ultrasound technician, or sonographer, will put a special gel on your belly (it may be a little chilly, but some offices use a special warmer to make the gel more comfortable). An ultrasound wand is then moved across your belly and your baby's image will show up on a special screen.

Why Will You Have an Ultrasound Scan?

Most women have two ultrasounds during their pregnancy -- one between 10 and 12 weeks and the other around 20 weeks. The earlier scan is used to date the pregnancy and gives a more accurate due date. This is important because an accurate due date will help you make important decisions about your pregnancy, such as when to induce if your pregnancy goes overdue. It's also important to know how far along you are for certain tests, such as the one for Down Syndrome.

Your second sonogram is used to check for any physical abnormalities. At this point in your pregnancy, your baby's anatomy will be developed enough so that your sonographer can take accurate measurements of your baby's head, abdomen and thigh bones. He or she will also be able to look at the baby's heart, stomach, bladder, kidneys, spine, hands and feet.

In this later ultrasound, some parents are able to find out if they're having a boy or a girl. Don't be disappointed if the results aren't revealed during your ultrasound scan though -- some babies aren't in the proper position to find out.

What Can Your Ultrasound Scan Detect?

In your early ultrasound scan, your sonographer will be looking for a single pregnancy, twins or even triplets. Some birth defects, such as Spina Bifida, can also be found during a sonogram. It can also give you insight on whether your baby has certain chromosome abnormalities, but these cannot be diagnosed with ultrasound alone.

Is It Safe to Have a Sonogram?

Ultrasounds have been used for more than 30 years and there are no known side effects from them. Some women have them frequently if there are health concerns with their baby. Some people become concerned because ultrasounds are often mistaken for other tests that have a radiation risk, like X-rays and CT scans. However, because an ultrasound scan uses sound waves, there's no radiation concern.

Is an Ultrasound Scan Necessary?

Some women do choose to forgo a sonogram, usually because they don't want to know if there's anything wrong with the baby before it is born. However, this is typically not recommended because some problems can be treated before the baby is even born. If you don't want a sonogram for any reason, talk it over with your healthcare provider.

Can I Get a 4D Sonogram?

Some doctor's offices and private clinics now offer special 4D ultrasound scans. These ultrasounds let you see the features of your baby's face. They're not usually covered by insurance, but you can pay out of pocket if you'd like a 4D ultrasound. They're usually done between the 26th and 32nd week of pregnancy.